1)
2 moli n moli
NaOH + HCl --> NaCl + H2O
1 1
=> n = 2x1/1 = 2 moli NaCl
nr.moli = m/M, M.NaCl = 23+35,5 = 58,5 g/mol
=> m.NaCl = nxM = 2x58,5 = 117 g NaCl
3)
520g Zn impur .................... 100%
m.pura ................................. 75%
= 390g Zn pur
390g n moli
Zn + 2HCl --> ZnCl2 + H2
65 1
=> n = 390x1/65 = 6 moli H2
4)
250 kg impur .......................... 100%
m.pura ........................................ 80%
= 200 kg carbonat pur
200 kg m kg
CaCO3 --toC--> CaO + CO2
100 56
M.CaCO3 = 40+12+3x16 = 100 kg/kmol
M.CaO = 40+16 = 56 kg/kmol
=> m = 200x56/100 = 112 kg CaO
